Further to previous posts in praise of moving around rather than too much sitting, here's a link to a Washington Post article which makes the same point.  It's by a teacher who shadowed two pupils for two days, and was shocked by what she learned, not least that "Students sit all day, and sitting is exhausting".
Click here to read the article (there's also an interesting anti-sarcasm message.  Anyone know a teacher that could benefit from taking that on board?)

Much of my work as an Alexander Technique teacher involves guiding people to perform better by getting rid of unhelpful tension.  It's good to know that four-time Olympic sprint champion Michael Johnson is on the same page.  He says: "It sounds counter-intuitive because sprinting is highly ballistic but you have to be relaxed.  People tend to tense up but if your muscles are tight your arms will come across your body and you won't be as fast.  You don't want to clench your fists or run with your fingers out so I would rest my thumb gently on my forefinger, which gives me just the right amount of relaxation and focus."   (FT Magazine, December 6/7 2014)

About twenty years ago, while I was training to be an Alexander Technique teacher, I attended an 'Art of Running' workshop led by Malcolm Balk, a Canadian Alexander Teacher and former Olympic runner.  Now, on the Guardian's website, Malcolm offers advice on how to walk with good technique, in order to transform walking from a task into a healthy pleasure.  "Try and let go of the urgency that pollutes much of our lives and just enjoy the quality of the movement."  Click here to read Malcolm's five steps to walking well.